Musnad Ahmad 541:6

Muhammad ibn Ja‘far narrated to us, he said: Hajjaj narrated to us, he said: Shu‘bah informed us, ‘Amr ibn Dinar informed us, from a man from the people of Egypt who narrated that ‘Amr ibn al-‘As gave gifts to some people, and he favored ‘Ammar ibn Yasir. It was said to him [about that], so he said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: "The rebellious faction will kill him."